Radio antenna



F. L. PARSONS Jan. 9, 1951 m mm A mb DI 2 w Mv n m W w m o M /l 0 29 W mFiled July 1, 1948 F. L. PARSONS Jan. 9, 1951 RADIO ANTENNA Filed Julyl, 1948 3 Sheets-Sheet 2 v INVENToR. kf/CKLPKsO/vs BY Ww. www

Jan. 9, 1951 l F Lfy EARSQNS 2,537,481

RADIO ANTENNA Filed July l, 1948 3 Sheets-Shea?l 5 /764 PXI 176 E174174" j' '170' Xl 1729 INVENTOR. EQEDfPmf L Psazvs Patented Jan. 9, 1951RADIO ANTENNA Frederick L. Parsons, Upper Montclair,` N. J., as'-signor` of one-half to Walter J (Smith, Jr., New

York, N. Y.

Application July 1, 1948, serial No. 36,490

14 Claims. (Cl. Z50-33) This invention relates to a radio antenna, moreparticularly to an antenna of the selectively eX- tensible andretractable type. The antenna of the invention is particularly adaptedfor use on land and water vehicles, although it is not limited to suchuse.

The invention has among its objects the provision of an improved antennain which the impulse receiving and/or transmitting antenna member iscontinuous and is provided with a telescopic non-electrically conductingshield or cover.

The invention has as a further object the provision of an improvedreeling device and driving mechanism therefor for extending orretracting the impulse receiving and/or transmitting an` tenna member,the reel and driving unit being self-contained and beingcharacterized byits compactness, simplicity, and positiveness of control.

Yet a further object of the invention, in one embodiment thereof,resides in an improved means for connecting the antenna member to theradio apparatus whereby a continuous un= broken conductor is interposedbetween such member and the set.

A still further object of the invention, in anv` other embodimentthereof, lies in the provision of an improved dipole radio antenna ofthe retractable type and the operating mechanism therefor.

These and further objects `of the invention will be more readilyapparent in the following description of the. preferred embodiments ofthe radio antenna Within the teaching of the invention.

In order to provide efficient short Wave radio communication for landvehicles such as automobiles, tanks, and for Water vehicles such asboats, it is necessary that the antenna be of f appreciable length, inthe first two preferred embodiments described herein the extendedimpulse receiving member being 17% ft. overall in typicalv tion, of theoperator. It is further very desirable that such antenna shall beconstructed as to be a selfucontained unit so as to be easily mountableon, or demountable from, the vehicle. Previous antennas of this typehave been compli-` cated, diflicult to control, and hard to install.

Such previous antennas furthermore have been objectionable in that theimpulse receiving and/ or Y transmitting member Was sectional, thusintrolong and extend too high to be left at all times in fully extendedposition, and must be retracted from time to time, as when an automobileso ducing numerous mechanical connections into the circuit which soonbecame faulty when exposed to the weather.

As indicated above, the antenna of the present invention overcomes suchdiculties by providing a positive, easily controlled, compact drivingunit for the antenna and by providing a continuous impulse receivingand/or transmitting circuit. The invention will be more readilyunderstood by reference to the drawings appended hereto,- showingpreferred embodiments of the antenna of the invention, in which Fig. 1is a view in side elevation of the radio antenna of the rst describedembodiment, the point of view being taken along the line I-I in Fig. 2;

Fig. 2 'is a fragmentary' end view of the struc ture of Fig. 1, thepoint of View being taken along the line I--II in Fig. l;

Fig. 3 is a view in vertical crosssction through the structure shown inFigs. 1 and 2, the section being taken generally along the line III-IIIin Fig. 4 but the front portion of the motor and its driving pinionbeing shown;

Fig. 4 is a View in transverse section through such structure, thesection being taken along the line IV-IV in Fig'. 1;

Fig. 5 is a view in transverse section through a portion of the mainbody casing of the rst embodiment of the antenna, the section beingtaken along the line V-V in Fig. 1;.

Fig. 6 is a view in vertical cross-section of a second embodiment of theantenna of the invention, section being taken in a manner similar tothat of Fig. 4;

Fig. 7 is a schematic wiring diagram of the control circuit for thedriving motor of the reeling 4device for either of such two previouslyshown embodiments when a D. C. source of supply is employed;

Fig. 8 is a schematic wiring diagram showing the control circuit for themotor of such embodiments when an /A. C. source is employed;

Fig. 9 is a fragmentary view in side elevation of a third embodiment ofthe antenna of the invention, such embodiment being a dipole antenna;

Fig. 10 is a fragmentary view in plan of the structure shown in Fig. 9;

Fig. ll is a view partially in vertical section and partiallyin'elevation of the structure shown in Figs. 9 and l0, the section beingtaken along XI-Xl in Fig. 9; and

Fig. l2 is a view in vertical section through the main housing of suchthird embodiment of the antenna, the section being taken along the lineXII-XII in Fig. l0.

The rst embodimentJ of the antenna described is shown in Figs. 1 5,inclusive. Such antenna includes a main, reel and motor enclosing,housing 2 made of insulating material such as a reinforced syntheticresin of which that known as Micarta is typical. Housing 2 is generallyof cylindrical form but has rising therefrom a generally tangentiallydisposed hollow extension B on which is carried the extensible impulsereceiving and/or transmitting antenna member and cover structuretherefor, indicated generally by the reference character d. The antennais shown mounted on a supporting member 8, which may be a part of anautomobile for example, there being provided a resilient connecting andsupporting means generally indicated at I between the support and theantenna unit, member I0 providing an electrically insulating barrierbetween the support and the antenna. The antenna housing 2 has providedon its outer end a removable cover l2, which may 'be made of a metalsuch as aluminum, the outer end portion of the covering being shown atlll and the side wall thereof, which is generally in the shape of acylindrical flange telescoping the end of the housing, being shown ati6. The cover is held in assembled position on the housing by means ofthe nuts i8 screwed onto the studs l@` which project from a xed part ofthe structure within the housing, in this case the forward end of hub5S.

The imp-ulse receiving and/or transmitting member of the antennaconsists of the stranded cable, designated S6 in its straight extendedportion, and B in that portion where it exists in coiled condition. Theantenna cable is made of sui'icient stiffness so that a thrust on itsinner coiled end will extend it into fully elevated position withoutundue buckling, but at the same time it is suiciently ilexible so aseasily to be coiled on the reel, subsequently to be described, withoutacquiring a permanent set. The straight portion 3B of the antenna cableis provided with a series of telescopic mounting cover members in theform of tubes along the axis of which cable 30 extends, the largesttube, designated 20, being iixedly mounted on the housing 2 by havingits lower end telescoped into the bore 32 provided in extension 6, suchextension being split at its upper end and being clamped tightly abouttube by the squeeze clamp 313.

The other telescopic tubes, successively designated 22, 2d, and 2t,reading in an upward direction, slide within each other as shown, beingguided by the short tubular sleeve members 2l within the next lowertube, one such sleeve being placed at the upper end and one being spacedsome distance below such end of the tube. The lower end of each of theslidable tubes is provided outwardly thereof with a short sleeve 23which functions as a stop member when it abuts the lower sleeve 2l. Theantenna cable cover is completed -by the cap 2B anixed to the upper endof tube 26, such cap incorporating means (not shown) to which the outerend of cable 30 is aixed. It will be evident thatv when the cable isthrust upwardly it carries with it the cover sections until finally theylie fully extended, and that when the cable is retracted it pulls themdownwardly until they reach a fully telescoped position. In Fig. 1 theaerial is shown in a partially extended position.

It is preferred, in accordance with the invention, to make each of tubes29, 22, 2li, and 26 as well as the cap 28, of an electrically insulatingplastic material. In such case the sleeves 2l and 23 are likewise ofsuch plastic material and may be ailixed to the tubes by means ofplastic cement. Such construction is preferred because it fully protectsthe antenna cable from the atmosphere and includes in the impulsereceiving and/orV transmitting circuit no connections which may becomefaulty due to corrosion, wear, etc. In some instances, however, it maybe desired to make the upper tube 25 and cap 23 of metal, since positiveconnection between the antenna cable and such members may easily be madeand maintained.

The t between the outer surfaces of telescopic tube members constitutingthe cover portion and sleeve members 2| is such that little if anymoisture can penetrate between such sections. There is, however,provided a sealing means between the atmosphere and the interior oihousing 2 in the form of a packing through which the antenna cable runs.Such packing preferably takes the form shown in Figure 3, in which thereis shown a iirst metal washer 36, a rst graphite impregnated felt washer38, a second metal washer 40, and a second similar felt washer 42.

The structure of the cable reeling device, the driving and controllingmeans therefor, and of the antenna housing mounting means lll will bemore clearly apparent by consideration of Fig. 4. As there shown, thedevice is adapted for mounting on the support 8 at a hole Ml provided insuch support. Aflixed to support 8, as by screws 48, is a mounting plateit on the outer face of which is mounted a resilient electricallyinsulating disc 50. Such disc 5t may be made of an elastomer such asnatural or synthetic rubber. On the outer face of disc 5B there ispositioned a retaining ring 52 secured to member i6 by means of thescrews 54 which extend through member 50. The antenna reel hub 56, madein this instance of metal, provides the 'main support for the antennastructure. Such hub is provided at its rear end with a sleeve 62 ofreduced diameter, such sleeve being received within the cylindricalportion 66 of a mounting member having a radial flange 64 engaging theouter face of disc 50. The peripheral edge of flange 64 is spacedsomewhat from the inner edge of ring 52 so as to allow appreciableflexing of disc with no danger of metallic contact through the parts ofthe mounting member I. The mounting member is completed by the outerring 68 which engages the outer face of disc 50 and the forward edge ofcylindrical sleeve 66, member 68 being held in place by the springwasher l0, which in turn is retained on sleeve portion 62 of the hub bythe split retaining ring member 12 which is snapped into an annulargroove on the outer end of part 62, as shown. Rotation between hub 5Sand the mounting member I9 and thus support 8 is prevented by the hubretaining pin 1B, which extends, as shown, into openings in the rear ofradial flange on the reel hub and in the iiange 64 of the inner mountingmember, respectively.

The reel hub 56 is provided, forward of flange 60, with an annular wal158, the intermediate 5. portion thereof being thickened as shown andbeing provided with'screw threads 16 on its exterior, the extremeforward end 18 of the hub being of reduced thickness and unthreaded. Thehub is provided with an opening therethrough, the forward end of theopening being of a somewhat reduced diameter as shown at 80, for thereception of the forward end of electrical motor 82 which ts tightlythereinto. The motor is retained in the bore by a set-screw, as shown.

The generally cylindrical casing member 2 is provided at its rear endwith an inwardly directed radial flange 84 which fits within an annulargroove on the forward face of flange 60 of the hub at its outer edge, asshown in Fig. 4, the two parts being connected by screws, as shown. Themain cylindrical wall portion of casing 2 is designated 86. Such wallhas integral therewith at its forward edge a thinner portion 88 oflarger diameter, which with yportion I6 of the removable cover providesan enclosure for the forward end of the reel. An annular gasket 90 isinterposed between the edge of cover portion I6 and of housing portion88.

The antenna cable reel 92, made of strong electrically insulatingmaterial such as Micarta, cooperates with the antenna cable sleeve 94,which may be made of the same material, so that the coiled cable 30 iscaused to lie on the reel in a tightly coiled condition. The sleeve andreel rotate together, and the reel in addition travels lengthwise of thehub, so as to present that portion of the cable being payed off the reelin accurate guided position into the cable guiding channel 95 providedin member 2 beneath extension 6 of the housing. Mounting of the reel andsleeve to accomplish such result is eiected as follows: Reel 92 isprovided with an inwardly directed web or flange 96 having a centralaxial opening therein provided with screw threads 98 accurately engagingscrew threads 'I6 on the hub. Thus rotation of the reel causes it toprogress axially of the hub. Sleeve 94 is provided with a cylindricalportion |02 surrounding the reel, the inner surface of part |02 of theSleeve closely engaging the outer surfaces of coils 30' of the antennacable. The sleeve is rotatably supported at its rear open end of partl|02, such part of the sleeve being accurately carried on the innercylindrical bearing surface of casing part 88. The sleeve has aninwardly directed radial ange |04 at its forward end, engagement betweenthe outer surface of such flange and the inner surface of cover part I4keeping the sleeve in place.

The pitch of threads 'I6 and 98 is made equal to the diameter of theantenna cable so that the reel travels suiciently to continuously thrustthe cable, by means of the end flange |06 on the reel, accurately into,or to withdraw it from the channel 95, depending on the direction ofrotation of the reel. The portion of the coiled cable which has justbeen fed off the reel and is about to be fed into channel 95, after ithas left the forward end of sleeve part |02, is in engagement with theguiding channel in wall 86 of the casing provided by surfaces |08 and||0. Surface |08 is a portion of a cylinder lying as a prolongation ofthe inner surface part of sleeve |02. Surface ||0, elements of which areat right angles to elements of surface |08, lies on a helix having thesame pitch as the coils of cable 30'.

1 Motor 82 has provided on the driving shaft at the forward end thereofthe pinion I I2, which meshes with two intermediate gears |I4 rotatingon the xedimounting pins I|6 projecting from the forward end of the reelhub. Gears II4 alsol mesh with the internal ring gear ||8 formed on theinner edge of flange |04 of the sleeve., Such gears provide a positivereducing drive .be,

`in the web 96 of reel 92 so that when the sleeve is rotated, the reelis rotated with it but slides relative thereto.

There are further provided within the housing the two limit switches,|20 and |22, supported on the hub 56 as shown. Such switches,

which may be of a conventional normally closed, single pole, springpressed type, are mounted so that the contacts of each are opened whenthe operating member of either of the switches is contacted by the web96 of the reel. The control circuit for motor 82, incorporating suchlimit switches, will be more fully discussed below.

In the embodiment of the antenna discussed above contact between theantenna cable and the antenna lead is provided by means of a springpressed brush which `bears upon the cable within the channel 95. InFigs. 3 and 5 the brush is shown at |26, its location in the casingbeing more clearly shown in Fig. 3. A bore E24 is provided in casingpart 6 so as to intersect the channel 95. Within such bore is positionedthe brush |26, which pressed into contact with the straight cableportion 30 by the helical coil spring |28 which is retained in the boreby the plug |30. The antenna lead wire |32 is connected to the brush andis brought within the casing and thence outwardly through the bore 03 inthe rear portion of the hub member. Although in this instance theantenna lead is shown as a single conductor, itis to be understood thatpreferably such lead will be shielded.

In the embodiment of the antenna shown in Fig. 6 the parts which exactlycorrespond to those shown in Fig. 4 are designated by the same referencecharacters. The embodiment now to be described differs from that abovediscussedA as to the character of the means for effecting connectionfrom the antenna cable to the radio. set, and the structure of the meansby which' the main housing 2 is attached to the support 8. In theembodiment shown in Fig. 6, the reel hub, generally designated |34,which preferably is made of metal, is provided with a radial flange |36and with a rear portion |38 of reduced diameter beyond such flange. Thehousing r mounting means consists of the flanged mounting sleeve member|40 secured to member 8 by studs |42, and of a composite resilientinsulating bushing interposed between the cylindrical portion of member|40 and partV |39 of the hub..

Such bushing consists of an outer metal sleeve |44, an intermediateresilient insulating sleeve |46 made of rubber or synthetic rubber, andan inner metal sleeve |48 within member |46, sleeves |44 and |48 beingbonded to member |46. Portion |38 of the hub is inserted within innersleeve |48, the rear end of the former protruding through hole 44 in thesupport, the hub beingY retained by the nut |50 screwed onto itsthreaded rear end and contacting the rear edge of sleeve |48.

In this embodiment a continuous electrical connection is providedbetween the antenna cable and the radio set, and no cable contactingbrush is employed in housing extension 6'. Such con-V nection isprovided by bringing the` inner 2', 537,48 lllA |52 of the coiled cable30' through an opening into the interior of the reel 92 and bypermanently securing thereto the end of the flexible lead wire i545which extends through an opening in the web 95 of the reel. Within thehousing 2' there is provided a collapsible hollow support |55 upon whichcoils of the lead wire |54 are supported. The collapsible support may beeither in the form of a helical coil compression spring, as shown,succeeding turns |53, |55 and |52 of which are telescoped, the springbeing retained in place between the web 96' and the rear inner face ofcasing 2 by the expansive force of the spring. Alternatively support |55may consist of disconnected telescopic portions the end sections ofwhich are connected respectively to the web and casing, the centersection being prevented from sliding out of telescopic relation with theend sections by means of radial llanges which interengage at the fullyextended position of such support.

It will be seen that as the antenna cable is fed from the reel as thereel travels to the right, in Fig. 6, the flexible antenna lead willhave its coils more closely spaced with respect to each other. Theeective length of such lead remains substantially the same throughoutsuch travel, the collapsible support maintaining substantially theinitial size of the coils of the lead wire and preventing the tanglingof the coils thereof.

In Figs. 9-12, inclusive, there is shown a dipole antenna which embodiessome of the salient features of the two previously describedembodiments. Such antenna is adapted for ultra-high frequency radioreception and/or transmission, and must, for eicient operation, beplaced relatively high above its support. The antenna extending andretracting mechanism of the present invention is admirably adapted foruse in such dipole antenna since it is readily controllable from adistance.

In this embodiment there is provided a central hollow housing |64 madeof insulating material such as Micarta, such housing having a splitsleeve |56 on the bottom thereoir to receive the upper end of a verticalsupporting member (not shown). Casing |54 provides the support for twooppositely extending extensible antenna members, there being at the leftin Fig. 9 a anged supporting member H38 on which is ixedly mounted therst hollow cable covering member |10, the two movable telescopicallymounted cover members H2 and |14, together with cap |76 for the. latter,being mounted thereon. The flexibie antenna cable |18 is connected tocap |16 as in the first embodiment. Preferably members |58, |10, |12,l', and |16 are made of insulating plastio material. The antenna memberto the right of the casing in Fig. 9 is similar to that above described,corresponding parts being designated -by the same reference charactersprimed.

As shown in Fig. l the oppositely extending :antenna members aredisplaced somewhat laterally from each other. This arises from the factthat each extensible antenna member has its own reel, the reels beingmounted on a common axis along which they are spaced. Connected to themain housing ifli, within which such reels are contained, is the motor,gearing, and limit switch containing housing |85, the housing parts |55and 58d being connected by means of the fixed shaft |813 extendinglongitudinally through them and through the removable end plate |82, theshaft being secured at the left in Fig. by nut |86 and at the right bynut 588.

8 Shaft |84, which is made of metal, is provided,Y as-seen in Fig. 12,in the portion within housing |64 with a right-hand threaded portion |90and a left-hand threaded portion |92. Such threaded portions, as will beapparent hereafter, pro-- vide the mounting for the hubs of therespective reels and cause them selectively to approach or. travel awayfrom each other` depending upon the direction of rotation of the motor|911. Such motor is mounted, as shown, in casing and is provided withthe driving pinion |95. Such pinion meshes with the large spur gear |98keyed to the sleeve 255 which is rotatably mounted on the left-hand endof shaft |84. The right-hand end of such sleeve provides the means to.drivev the first reeling device 252, shown at the left, the drive forthe second reeling device 204, at the right, being derived therefrom.Sleeve 25|]- is` pinned as shown to the hub 2| 4 on the sleeve 225 ofreeling device 252. Thus, when sleeve 200 rotates, it drives sleeve2li). A driving pin 220 iixedly connected to the radial flange 2|2 ofsleeve 2|!) slidingly extends through a bore in the web 2 I8 of reel 2|.The coiled cable 25S on the iirst reeling device feeds oi the reel intoa helical channel and thence is led through a guideway through thehousing wall into the extensible antenna member in the same manner asdescribedv in the iirst embodiment. The helical channel is provided inthe annular enlargement 222. in housing i-Gd, the left-hand edge of suchenlargement shown at 221% lying on aSpiraL |The right-hand reelingdevice is composedof the reel 232, a sleeve 22S having a radial liange228 and the hub 235 which rotates upon the smooth right-hand end ofshaft |84. The reeling device is also provided with a driving pin 235between sleeve and reel and the coiled cable 253 delivered therefrom isguided into a helical channel provided by the right-hand edge 238 ofenlargement 222.. The reels and slee-ves of this embodiment are made ofelectrically insulating material such as Micarta Driving of reelingdevice 252:4 from device 202 but in a reverse direction is effected bymeans of the bevel gear 22e on the outer open edge of the sleeve 2|f5`which meshes with the connecting bevel gear 24d. Gear 241i, whichrotates about -a vertical axis, is retained on cover plate 2&5 on, thevhousing by means of the retaining collar 248'. Gear; 25:4 in turn mesheswith a bevel gear 242 0nthe outer open end of sleeve 226. It will beseen that when sleeve 2510 is driven in one direction it drives sleeve226 in the reverse direction, the correspon'dingv reels thus beingcaused to travel, on their supporting threads selectively toward or awayfrom each other.

Connection between the antenna leads (not4 shown) and the two impulsereceiving membersy |18 and HS is eflected by means of brushes (notshown) affixedY in the housing |52. immediately inwardly of members |68and |68'. Since the construction and function of such brushes havealready been discussed', further description of them here isunnecessary.

The limit switches in this device are shown at 25D and 252. Cooperatingwith the limit switchesv is a movable switch actuating member in theform of aV nut 256 engaging screw threads 254 on sleeve 205;, the nutbeing provided with a radial iiange 258 and being prevented fromrotation by means of a longitudinal rib 260 on the inner surface ofhousing |188, such rib being engaged in a slot in flange 258. It will beseen that when sleeve 25B is rotated it causes nut 256 and vswitchcomponent or by the 'switch |22'.

'of wire 382 and limit switch |28.

' the motor.

9 flange 258 'to travel, the hand and pitch of threads 254 and thespacing of the limit switches being such that motor |94 will be stoppedthereby when the antenna, cables areboth either fully extended or fullyretracted.

In Fig. '7 there is shown a schematic wiring diagram for the currentsupplying and controlling circuitffor any one of the describedembodiments when employing a direct current source of supply for thedriving motor. For the purpose of simplicity motor 82 in this instanceis taken to be one which has a rotor composed of xed magnets and a field268 connected to the current source through a commutator driven by therotor. In a motor of this type a simple reversal of the leads to the eldwill effect reversal of rotation of the rotor.

The two supply wires L+ and L- are connected as shown by wires 262 and214, respective1y, to contacts of a switch composed of components 264and 216. The switch is so con- -structed that such two components areinterlocked, allowing only one to be placed in circuit closing positionat a time. The other upper contact of switch component 264 is connectedto the motor field by wire 266, and that of switch component 216 beingconnected to the commutator by wire 212. A lamp 218 is connected between'wires 266 and 212 so that when such wires are energized to drive themotor the lamp is lighted.

The two limit switches, |20 and |22, are normally closed except whentheir operating elements are depressed. When the reel is in the positionshown in Fig. 4 switch |29 is open but switch |22 is closed as shown inFig. '1. To elevate the antenna the control switch is actuated toelevate switch portion 264. Thus the circuit including wires 262 and268, the eld 268, the

commutator on the rotor 218, wire 212, switch |22, the bottom portion ofswitch 264, and Wire 214 to the lead wire L- is closed. The motor thenrotates in a forward direction and continues to rotate in that directionuntil either switch por- 'tion 264 is returned to neutral, orwhen limitswitch |22 is opened as the aerial reaches fully extended position andthe web 96 of the reel actuates such limit switch. Reverse operation ofthe motor is effected in the same manner, except that in this caseswitch component 216 is employed and rotation of the motor in reversedirection is stopped either by the opening of such opening of limitswitch |20. l

In Fig. 8, which depicts a schematic wiring as of the series type inwhich there are provided -two fields, one being wound in a reversedirection l from the other.

The wound rotor designated 288 may selectively be placed in series witheither the field 282 or the reversely wound eld 284.

The single phase alternating current supply is connected to lead wires288 and 298, wire 299 being connected to the contacts of a reversingswitch shown as having components 292 and 284 which are so connectedthat only one may be in contact closing position at a time. The upper4`contact of component 292 is connected to field 284 through the mediumof wire 388 and limit The lower contact of component 294 is connected toeld 282 through the medium A grounded shield 286 is provided about thethree leads to Indicating lamps k296 and 298 are connected as shown, onebeing lighted when the motor operates in a forward direction and theother being lighted when it operates in the reverse direction.

It will be apparent that the control circuit of Fig. 8 is such that whenswitch component 292 is closed eld 284 will be energized, assuming thatlimit switch |22' is closed, and the motor will be driven in a forward,antenna elevating, direction. The motor continues to rotate in suchdirection until field 284 is d-energized either by the opening of switchcomponent 292 or of limit switch |22. When switch component 294 isclosed, field 282 is energized to drive the motor in a reversedirection, the motor continuing to rotate in such direction until eitherswitch component 294 or limit switch |28' is opened.

Although for purposes of illustration I have described preferredembodiments of the radio antenna of my invention, it is'to be understoodthat the invention is not limited tl: ereto, but that it is capable ofconsiderable variation as to details.

The scope of the invention is therefore defined by the following claims.

I claim as new the following:

l. A reel for operating a exible antenna cable selectively to extend itsforward uncoiled end or to retract the same comprising a housing, a reelhaving a cylindrical periphery rotatably mounted within the housing, acable receiving guideway through the housing wall, an antenna cablesleeve cooperating with the peripheral surface of the reel to coni-inethe coiled cable on the reel to one thickness thereof, means to rotatethe reel, means responsive to reel rotation for moving said reellongitudinally along its axis at such Yrate as to continually maintainsuccessive turns of the cable in a predetermined relationship with andthroughout the surface of the reel, and a prime mover within the housingfor driving the reel.

2. A reel for operating a iiexible antenna cable selectively to extendits forward uncoiled end or to retract the same comprising anonrotatable cylindrical supporting member, ya housing spaced from andsurrounding -the supporting member,

a reel having a cylindrical peripheral surface disposed within thehousing and rotatably mounted on the supporting member, a cablereceiving guideway through theY housing wall generally opposite aperipheral'edge of the reel, an antenna cable sleeve having acylindrical periphery spaced from and cooperating with the peripheralsurface of the reel to confine the coiled cable ion the reel to onethickness thereof, a prime mover axially-disposed within the supportingmember, means to connect the prime mover to the sleeve member to rotatethe latter, means to connect the sleeve member and reel together forpositive rotation together, means to rotate said reel, means responsiveto reel rotation to axially move said reel along the'supporting member,including, a threaded portion on the supporting member, the portion ofthe reel engaging the supporting member having screw threads thereonengaging with those on the supporting member, the pitch of such threadsbeing substantially equal to the diameter of the cable, whereby the reeltravels along Vits axis as it rotates to maintain the cable payed oil ordelivered to the reel at its aforesaid peripheral edge accuratelyaligned with the guideway.

3. In the combination set vforth in claim 2, the supporting member beinga hollow hub, the prime mover being loca-tedl within such hollow hub,the

. -hub including means by which the reel may be -attached to an externalsupport.

4. IIn the combination set forth in claim 2, the prime mover being areversible electric motor, a

-` current supplying and controlling circuit for the motor, said circuitincluding switch means v for starting, stopping, and reversing rthemotor,

and means included in said circuit and responsive to the axial locationof said reel upon said supporting member to stop the motor both when theantenna cable is fully extended and when it is fully retracted. f

' 5. A reel for operating a flexible antenna cable selectively to extendits forward uncoiled end or to retract the same comprising a housing, a-

`centrally located shaft running lengthwise of the housing, a reelhaving a cylindrical'periphery rotatably'mounted on the shaft within thehousthe reel along its axis at such rate as to continually maintainsuccessive turns of the cable in a predetermined relationship with andthroughout the surface of the reel, `including a screw threaded portionon the shaft and a screw threaded portion of the reel cooperatingtherewith, means to rotate the reel, said means including a. prime moverwithin the housing, a sleeve on the shaft spaced from the reel, meansvdrivingly connecting the motor to the sleeve, and means drivinglyconnecting the sleeve and the reel to rotate the latter.

6. A duplex reel structure for operating two oppositely disposedflexible antenna cables selectively simultaneously to extend the forwarduncoiled end of each or to retract the same comprising a housing,oppositely directed laterally7 oiiset extensible antenna cable guidingmeans on opposite sides of the housing, the housing having a guidewaythrough its wall on each side thereof, each guideway cooperating withits respective antenna guiding means to conduct the lcable to thelatter, two similar coaxial cylindrical reels rotatably mounted withinthe housing, each reel cooperating with its respective guideway, eachreel having associated therewith means cooperating with the peripheralsurface of the reel to confine the coiled cable on the reel to onethickness thereof, means to move each reel along its axis at such rateas to continually maintain successive turns of the cable in apredetermined relationship with and throughout kthe surface of the reel,a prime mover Within the housing, and means connecting the prime moverto both reels to drive them simultaneously.

'7. A duplex reel structure for operating two oppositely disposediiexible antenna cables selectively simultaneously to extend the forwarduncoiled end of each or to retract the same comprising a housing,oppositely directed laterally offset extensible antenna cable guidingmeans on opposite sides of the housing, the housing having a guidewaythrough its wall on each side thereof, each guideway cooperating withits respective antenna guiding means to conduct the cable to the latter,a supporting shaft located longitudinally of the housing and centrallythereof, `two similar coaxial cylindrical Vreels rotatably `mounted onthe shaft within the housing, one

reel and its guideway being substantially a reversed counterpart of theother such parts, each reel cooperating with its respective guideway,and each being placed with its peripheral edge adjacent the other reelsubstantially opposite its respective guideway, each reel havingassociated therewith means cooperating with the peripheral surface ofthe reel to conne the coiled cable on the reel to one thickness thereof,said last named means comprising a sleeve member rotatably mounted inthe housing coaxial of the reel, the sleeve member having a cylindricalportion adapted to surround the peripheral surface of the reel and lyingparallel thereto, such cylindrical portion of the sleeve beinlT open atthe end confronting the peripheral edge of the reel from which the cableis payed out, a prime mover within the housing, means to connect theprime mover to the sleeve member associated with one reel to rotate suchsleeve, means to connect the two sleeve members together so that theyrotate in opposite directions, means to connect together the sleevemember and reel of each unit for positive rotation together, meansresponsive to rotation of said reels for axially moving said reels withrespect to said supporting shaft to continually maintain successiveturns of said cable in a predetermined relationship with and throughoutthe surface of the reels, including, oppositely threaded portions on thesupporting shaft, the portions of each reel engaging the supportingshaft having screw 'threads thereon engaging with one of those on thesupporting shaft, the pitch of such threads being substantially equal tothe diameter of the cable, whereby each reel travels along its axis asit rotates to maintain the cable payed off or delivered to the reel atits aforesaid peripheral edge accurately directed into. its associatedguideway.

8. in the combination set forth in claim 7, the prime mover being areversible electric motor, a current supplying and controlling circuitfor the motor, said circuit including switch means for starting,stopping, and reversing the motor, and means included in said circuitandresponsive to the axial 'location of the reels on the supporti-ngshaft to stop the motor both when the antenna cables are fully extendedand when they are fully retracted.

9. An extensible antenna, comprising, a flexible antenna cable, acasing, means in the casing to selectively coil the cable at its rearend and to uncoil it at such end thereby retracting its forward endtowards, and extending its forward end from the casing, respectively, anantenna cable cover composed or" a series of tubes of rgraduated sizestelesoopically mounted about the forward end of the cable, the tube atone end of such series being nxedly attached to the casing, the`remainder of the tubes being slidable, and the tube at the other end ofthe series being attached to the forward end of the cable, all tubes ofsaid cover being made of insulating material, and means for maintainingan integral electric contact with the antenna cable, said last-mentionedmeans including a coiled flexible antenna lead wire connected at one endadjacent Ythe rear end of said antenna cable, and telescoping means tosupport the coiled lead wire substantially coaxial of the coiled antennacable.

l0. An extensible antenna, comprising, a flexible antenna cable, atelescopic casing for said cable, means for selectively extending theforward uncoiled -end of said cable and -for retracting the same,including, a housing, a non-rotatable hollow hub contained within saidhousing, a reel member having a cylindrical periphery rotatably mountedon the hub, an antenna cable sleeve having a cylindrical peripheryconcentrically positioned with respect to the periphery of the reelmemberand spaced therefrom, said reel member and said antenna cablesleeve cooperating to provide an annular chamber to confine a singlethickness of coiled cable therein, means connecting said reel member andsaid antenna cable sleeve for rotation together, means disposed withinsaid hub for rotating said reel member and said antenna cable sleeve,and means responsive to rotation of the reel member for axiallydisplacing the reel member with respect to the antenna cable sleeve andthe hub at a predetermined vrate for maintaining successive turns of thecable in a predetermined relationship with and throughout the surface ofthe reel.

1l. The device in accordance with claim l0, including, means responsiveto the axial position of said reel member on the hub for limiting theaxial displacement of said reel member.

12. An extensible dipole antenna, comprising,y

a pair of ilexible antenna cables, telescopic casings for each of saidcables, means for selectively extending the forward uncoiled ends ofeach of said cables equivalent amounts and for equally retracting thesame, including, a housing, a nonrotatable shaft contained Within saidhousing, a reel for each of said antenna cables rotatably mounted onsaid shaft, a cable sleeve positioned concentric with each of the reelmembers for con-` fining the coiled cables thereon to one thicknessthereof, means for counterrotating said reel members, means associatedwith the reel members and said shaft for axially displacing the reelmembers with respect to their respective cable sleeves and the shaft ata predetermined rate for maintaining the antenna cables in apredetermined xed relationship with respect to the peripheral surfacesof the reel members. k

13. An extensible dipole antenna, comprising,

40 a pair of ileXible antenna cables, telescoping casings for each ofsaid cables, means for selectively extending the forward uncoiled endsof said cables equivalent amounts and for equally retracting the same,including, a housing, a reel member for each of said cables rotatablymounted within the housing, an antenna cable sleeve concentric with eachof said reel members for confining the coiled cables thereon to onethickness thereof, means counterrotating said reel members together withtheir respective antenna cable sleeves, means associated with said reelmembers and said last-mentioned means for axially displacing said reelmembers with respect to their respective antenna cable sleeves at apredetermined rate for maintaining successive turns of the cables in apredetermined relationship with and throughout the surfaces of thereels.

14. An extensible dipole antenna, comprising, a pair of flexible antennacables, telescoping casings for each of said cables, means forselectively extending the forward uncoiled ends of each of said cablesequivalent amounts and for equally retracting the same, including, ahousing, a nonrotatable shaft contained Within said housing, a reelmember for each of saidantenna'cables having a cylindrical peripheryrotatably mounted on said shaft, an antenna cable sleeve having acylindrical periphery concentrically positioned with respect to theperiphery of each of said reel members and spaced therefrom, each ofsaid kreel members and their respective antenna cable sleevescooperating to provide an annular charnber for confining a singlethickness of coiled cable therein, means connecting each reel member andits respective cable sleevev for rotation together, means forcounterrotating said reel members, and means responsive to rotation ofthe reel members for axially displacing each of said reel members withrespect to their respective cable sleeves and the shaft at apredetermined rate for maintaining successive turns of the cables in apredetermined relationship with and throughout the sur-k faces of thereel members.

FREDERICK L. PARSONS.

RiniriRENClss CITED The following references are of record in the le ofthis patent:

UNrrED STATES PATENTS Number Name Date 1,683,911 Morris Sept. 11, 19281,911,234 Meyer May 30, 1932 2,130,993 Dubilier Sept. 20, 1938 2,343,684Mace Mar. 7, 1944 2,365,886 Lehmann Dec. 26,1944 2,366,634 Ludwig Jan.2, 1945

